Vinyl-polyester-oxazoline resin reaction product



United States Patent 3,3628% VINYL-?LYESTER-@XAZGHNE RESIN REACTHON PRUDUCT Edgar L. Clark, ()alr Park, llL, assignor to Commercial Solvents Corporation, a corporation of Maryland No Drawing. Continuation of application Ser. No. 292,084, July 1, 1963. This application Feb. 23,

1967, Ser. No. 620,209

6 Claims. (Cl. 260-22) This application is a continuation of application Ser. No. 292,084, filed July 1, 1966, now abandoned.

My invention relates to maleic polyester resins containing stable vinyl groups and their method of preparation.

Maleic polyesters dissolved in styrene have been used extensively for casting or lay-up work where thick layers of resin are employed. Resins of this type have been found to be impractical, however, in uses requiring thin films which are exposed to the air because, under such circumstances the styrene evaporates from the surface of the film. The evaporation of the styrene is particularly noticeable when the films are subjected to any elevation in temperature.

I have now prepared resins containing vinyl groups in which the vinyl groups do not escape from films of the resins even when heated. Also, my novel resins have increased flexibility and adhesive properties as compared no definite and exclusive structural formula for dimerized linoleic acid, it is sometimes represented as follows:

An aliphatic dibasic acid of at least 10 carbon atoms is necessary to give the product the desired properties. With such acids, the product is a heavy viscous liquid and readily handled as such in the further reaction with formaldehyde. Aliphatic dibasic acids of shorter carbon chain length and aromatic dibasic acids give unmanageable products, e.g. hard solids. I have found that a molar ratio of the aminomethane to fatty acid of about 1.5:1, i.e. about 3:2, must be employed to obtain a desirable product. I have found that the employment of lower molar ratios, i.e. of about 2:2, produces an unmanageable gel, apparently because of random cross linking of the components. Temperatures in the range of somewhat above 400 F., e.g. about 440 F., insure that all of the amino groups of the aminomethane are converted into the oxazoline rings. A temperature range of about 425 F. to 475 F. is generally satisfactory. The reaction is believed to proceed generally in accordance with the following equation, in which R in 1 from the aliphatic dibasic acid contains at least 6 carbon atoms:

CHe-O to styrene cross-linked maleic polyester resins. The novel resins are useful as molding and coating resins.

The resins of my invention are reaction products of maleic anhydride and certain vinyl-polyester oxazoline products. The vinyl-polyester-oxazoline products are reaction products of formaldehyde and a polyester-oxazoline product of the reaction of tris (hydroxymethyl) aminomethane and an aliphatic dibasic acid of at least 10 carbon atoms having a saturated carbon atom in the alpha position to the carboxyl groups.

The resins of my invention can be prepared by first reacting the aliphatic dibasic acid with tris (hydroxymethyl) aminomethane to produce the polyester-ox-azoline product which is then reacted with formaldehyde to produce the vinyl-polyester-oxazoline product. This vinylcontaining product is then reacted with maleic anhydride to produce a vinyl-polyester-oxazoline maleic resin containing vinyl groups and having varying degrees of hardness and flexibility determined by the quantity of maleic anhydride reacted.

In the preparation of the polyester-oxazoline product, tris (hydroxymethyl) aminomethane is reacted with an aliphatic dibasic acid of at least 10 carbon atoms, having a saturated carbon atom in the alpha position to the carboxyl groups, in a molar ratio of about 3 moles of the aminomethane and about 2 moles of acid and at elevated temperature sufiicient to convert the amino groups to oxazoline rings. The useful acids include saturated acids of about 10 to about 36 carbon atoms such as sebacic acids, HOOCCH (CH CH COOH, and unsaturated acids such as dimerized linoleic acid, both of which possess the required alpha carbon atom, necessary for formation of the vinyl group by reaction with formaldehyde. The dimerized linoleic acid can be pure dilinoleic acid or the commercially available product which includes a minor amount of trimerized acid. While there is The extent of the reaction of the acid and the aminomethane can be determined by testing for the acid number of the reaction mixture. Usually when an acid number of less than 4 is obtained, the reaction has been completed to a satisfactory degree.

In the preparation of the vinyl-polyester-oxazoline product, formaldehyde is reacted with the polyesteroxazoline product I in a molar ratio of about 1.5 to 3.5 moles of formaldehyde per mole of polyester-oxazoline product and at elevated temperature. While satisfactory products can be formed by the use of only about 1.5 moles of formaldehyde it is desirable to use about 3 moles since there are three alpha carbon atoms available for reaction for each molecule of the polyester-oxazoline product I produced from the 3:2 molar ratio of the aminomethane and acid. Preferably, a small excess of formaldehyde is used over the molar ratio of 3:1 formaldehyde to the polyester-oxazoline product, e.g. about 3.5:1. Advantageously, as low an elevated temperature as possible is employed in this reaction in order to prevent random reaction of the vinyl groups between molecules which results in unmanageable gels, For example, an unmanageable gel is formedat temperatures of about 500 F. and above. The formaldehyde is preferably added to the polyester-oxazoline at temperatures below about 270 F., before raising the temperature, to prevent the formaldehyde from boiling off. A temperature range of about 250 to 450 F. is generally satisfactory. The reaction time is generally about 3 hours or less and it is preferred to employ a reaction time somewhat shorter than 3 hours in that excessive reaction times tend to create a reaction product which becomes too stiff to handle in the further reaction with maleic anhydride, without the use of solvents. The reaction of the polyesteroxazoline and the formaldehyde is believed to proceed compound believed to have the Formula II described in accordance with the following equation: above. The product is a soft, flexible resin soluble in Polyester-oxazoline (I) 301120 (vinyl-polycstenoxazoline II) In the preparation of the vinyl-polyester-oxazoline alcohols, ketones and aromatic hydrocarbons. A 50% resin, maleic anhydride is reacted with the vinyl-polysolution of the resin had a Gardner Holt viscosity of ester-oxazoline reaction product II in a molar ratio of A. about 1 to 5 moles per mole of the reaction product and The vinyl-polyester xazoline compound obtained in at elevated temperature. This particular reaction is be- Example 2 was reacted in the following examples w th lieved to be a fusion in which the maleic anhydride ring differing quantities of maleic anhydride to produce resins opens and reacts with the free hydroxyl groups of the of varying degrees of hardness and flexibility.

vinyl-polyester-oxazoline product to form the half ester.

While the maximum theoretical amount of maleic an- EXAMPLE 3 hydride that can be reacted per mole of the vinyl-poly- Maleic vinyLPOIyeSIQFOxQZOZiM resin ester-oxazoline product II is 5 moles since there are 5 free hydroxyl groups available with which the maleic A 100 gram Sample 111015) of the Product anhydride can react, in actual production I have found pl 2 Was heated with 33 grams -3 3 of malelc that only 4.5 moles :of maleic anhydride per mole anhydfldfi to a temperature of until a clear, of the vinyl-polyester-oxazoline compound is all that can p on glass Was f All this tune grams of f be employed in the reaction without leaving a contertiary butyl peroxrde was added and then the entire siderable amount of unreacted maleic anhydride in the InlXmYe was Poured Into Heatlng at a p final reaction product. The amount of maleic anhydride tuft? 0f was contlnued n A h d can be varied between bo t 1 t 5 moles per l f block of resin was formed. The high malelc resin of this vinyl-polyester-oxazoline product to achieve Varying example can be used as a potting resin. degrees of hardness and flexibility in the final product, 30 EXAMPLE 4 low ratios providing more flexibility and high ratios harder resins. Generally, lower temperatures tend to Maleic-vinyl-polyester-oxazolinc resin favor the fusion of the maleic anhydride and the vinylpolyester-oxazoline product.Atemperature range of about A 100 gram Sample 7 mole) of the Product 250 to 0 R is generally satisfactory of Example 2 was heated with 25 grams (0. 24 mole) My invention will be further illustrated by the folof male: anhydrlde to a tempfaramre of 300 f lowing ex l was held at this temperature unt1l a 20 second cure time EXAMPLE 1 on a 392 F. cure plate was obtained. At th1s time 120 grams of xylol was added and the mixture was cooled polyesiefioxdzoline r a tion product to room temperature. After cooling, 2 grams of benzoyl I hi exam 1 trig (hydroxymethyl) aminomethane peroxide dlssolved 111 10 grams of xylol was added and was reacted with dimerized linoleic acid. The dimerized then gran} of 6% cobalt naphthalene was The linoleic acid was a commercial product sold under the resultmg mxture was cast as a 3 H111 film on a tm Plate trade name EmPol 1018 Dimgr Acid made by Emery and baked for 30 minutes at 350 to a tough, mar Industries Inc Cincinnati, Ohio This Product is resistant film. This low maleic resin can be used as tained by dimerization of the linoleic acid available in K i rash; h b 1 th 1 i soya, cottonseed, corn and linseed oils. It typically coms y t e a We exaglp f 5 61c res.ns prises about 83% dimerized acid, about 17% trimerized of my mvemlon can be so o ave varymg acid and a trace of monomeric acid degrees of hardness and fieXlblllty ranging from a hard A quantity of 365 grams (3 moles) of ms (hydroxy block resin to a tough, mar res stant film depending upon methyl) aminomethane and 1120 grams (2 moles) of the.quant1ty Of.ma1e1.c anhydnde employed malelc Empol 101s dimer fatty acid (dimerized linoleic acid) my W can be mOldmg and were mixed together and heated slowly to 440 F. Samcoatmg compqsmons m mannier slmllar known ples of the reaction mixture were removed and tested polyeter moldmg coatmg resms' The resms can be for acid number. When an acid number below 4 was m.contact hand lay-up or obtained the reaction of the aminomethane and the lammatmg procedures a manner known the fatty acid was substantially complete. The prdouct ob- In Such Procedures whefe i films are required they tained was a polyester-oxazoline compound and is beare prov1dd the resms wlthmlt loss of vlilyl groups lieved to have the Formula I described above unlike the prior styrene based resins. The resins formed The product is a very heavy viscous liql'lid flowing from higher amounts of maleic anhydride are particularly slightly at room temperature and flowing freely at elevated useful as potting. .resms for .encasmg incapsulrfltmg temperature. The product is soluble in alcohols, ketones componants. ensmve molsmre an 0t er envlron' and aromatic hydrocarbons mental conditions such as for example coils, transformers, circuits, etc. The resins exhibit low shrinkage during EXAMPLE 2 polymerization and thus are useful for polymerization in situ in casting procedures where close dimensional V1nyl-polyester-oxazolmereaction product tolerances are required. The lower maleic content resins After the acid number of below 4 was obtained in can be advantageously employed as coating compositions Example 1, the heat was removed from the polyesterfor masonry, wood and metal. In such use, the resins oxazoline product and when the temperature dropped are used as vehicles to prepare coating formulations, e.g. to 275 F., 3.5 moles of form-aldehyde, as paraformaldepaints, lacquers, varnishes, enamels, by inclusion with hyde, were added. The temperature was then gradually suitable pigments, driers, solvents, diluents, etc., in a raised to 390 F. and held there until a cure of 70 manner known to the art and can be applied in amanner seconds was obtained on a 392 F. cure plate. The known to art for air curing or force curing, by heat product was cooled and was a vinyl-polyester-oxazoline or the use of accelerators. Such coating compositions have good adhesive properties thus further enhancing their value as coating compositions.

I claim:

1. The vinyl-polyester-oxazoline resin reaction product of (a) about 1 to 5 moles of maleic anhydride per mole of (b) the vinyl-polyester-oxazoline reaction product of about 1.5 to 3.5 moles of formaldehyde per mole of the polyester-oxazoline reaction product of tris (hydroirymethyl) aminomethane and an aliphatic dibasic acid of about to about 36 carbon atoms having a saturated carbon atom in the alpha position to the carboxyl groups in a molar ratio of about 3 moles of tris (hydroxymethyl) aminomethane and about 2 moles of acid said reaction of maleic anhydride and vinyl-polyesteroxazoline reaction product being conducted at a tempera ture of about 250 F. to about 350 F.

2. The vinyl-polyester-oxazoline resin reaction product of (a) about 1 to 5 moles of maleic anhydride per mole of (b) the vinyl-polyester-oxazoline reaction product of about 1.5 to 3.5 moles of formaldehyde per mole of the pOlyester-oxazoline reaction product of tris (hydroxymethyl) aminomethane and dimerized linoleic acid in a molar ratio of about 3 moles of tris (hydroxymethyl) aminomethane and about 2 moles of acid said reaction of tmaleic anhydride and vinyl-polyester-oxazoline reaction product being conducted at a temperature of about 250 F. to about 350 F.

3. The product of claim 2 in which the amount of formaldehyde is about 3 moles per mole of polyesteroxazoline reaction product.

4. The method of preparing a vinyl-polycster-oxazoline resin reaction product which comprises reacting tris (hydroxymethyl) aminomethane and an aliphatic dibasic acid of 10 to 36 carbon atoms having a saturated carbon atom in the alpha position to the carboxyl groups in a molar ratio of about 3 moles of tris (hydroxymethyl) aminomethane and about 2 moles of acid to form a polyester-oxazoline reaction product and reacting said product With about 1.5 to 3.5 moles of formaldehyde to form a vinyl-polyester-oxazoline reaction prodnot and reacting said product with about 1 to 5 moles of maleic anhydride at a temperature of about 250 F. to about 350 F.

5. The method of preparing a vinyl-polyester-oxazoline resin reaction product which comprises reacting tris (hydroxymethyl) aminomethane and dimerized linoleic acid in a molar ratio of about 3 moles of tris (hydroxymethyl) iaminomethane and about 2 moles of acid to form a polyester-oxazoline reaction product and reacting said product With about 1.5 to 3.5 moles of formaldehyde to form a vinyl-polyester-oxazoline reaction product and reacting said product with about 1 to 5 moles of maleic anhydride at a temperature of about 250 F. to about 350 F.

6. The method of claim 5 in Which the formaldehyde is reacted in an amount of about 3 moles.

References Cited UNITED STATES PATENTS 7/1946 Kuszuba 260-75 2/1960 Hughes 260-307.6

OTHER REFERENCES Shapiro, American Paint Journal, Vol. (1956), pp. -78. 

1. THE VINYL-POLYESTER-OXAZOLINE RESIN REACTION PRODUCT OF (A) ABOUT 1 TO 5 MOLES OF MALEIC ANHYDRIDE PER MOLE OF (B) THE VINYL-POLYESTER-OXAZOLINE REACTION PRODUCT OF ABOUT 1.5 TO 3.5 MOLES OF FORMALDEHYDE PER MOLE OF THE POLYESTER-OXAZOLINE REACTION PRODUCT OF TRIS (HYDROXYMETHYL) AMINOMETHANE AND AN ALIPHATIC DIBASIC ACID OF ABOUT 10 TO ABOUT 36 CARBON ATOMS HAVING A SATURATED CARBON ATOM IN THE ALPHA POSITION TO THE CARBOXYL GROUPS IN A MOLAR RATIO OF ABOUT 3 MOLES OF TRIS (HYDROXYMETHYL) AMINOMETHANE AND ABOUT 2 MOLES OF ACID SAID REACTION OF MALEIC ANHYDRIDE AND VINYL-POLYESTEROXAZOLINE REACTION PRODUCT BEING CONDUCTED AT A TEMPERATURE OF ABOUT 250*F. TO ABOUT 350*F. 